Oxygen transport represents one of the most fundamental of all biological processes, yet there are few means of transporting this gas. In addition, much remains to be learned of the interaction of oxygen with the few transport agents currently available. The present study which is being conducted collaboratively with Dr. Baldwin of Oxford University will yield new oxygen binding synthetic iron chelates and modified human hemoglobins. Compounds synthesized in England will be biologically tested in this laboratory in cell culture and animals for toxicity as well as for efficacy in transporting oxygen. Considerable effort will be placed on obtaining pure compounds and hemoglobin, and in analyzing for both the compounds themselves and their metabolic products. Any materials found suitable will be used in partial and total exchange perfusion experiments in animals. In particular oxygen affinity, oxygen off-loading and tissue oxygen uptake will be investigated in animals and in organ perfusions.